Clutch slips
Insufficient clutch pedal play. Check, make adjustments.
Defective clutch release mechanism. Check and make necessary repairs.
Defective clutch master or slave cylinders. Check and overhaul hydraulic clutch drive system.
The working surface of the clutch disc is worn out. Check and replace the disc if its friction linings are worn to less than 0.3mm above the rivet heads (see accompanying illustration).
Faulty servo unit (4.2 l models). Check, replace if necessary.
Note. Usually the first sign of a slipping clutch is a noticeable unreasonable increase in engine speed when taking on steep hills. To check the condition of the clutch, apply the parking brake firmly, chock the vehicle's wheels and shift the transmission into high gear, then slowly release the clutch at medium engine speeds. If the engine does not stall, the clutch is slipping. In order to avoid more serious damage to the clutch, the clutch must be inspected and any necessary repairs or replacements made without delay.
Clutch jerks and vibrations
The working surfaces of the driven disk are contaminated with oil. Check and replace disk if necessary. Find the source of the leak and eliminate its cause.
Loose or damaged disc hub. Check, replace disk.
The fastening of the friction linings of the driven disk has loosened. Check, replace disk.
Cracks appeared in the working surface of the pressure plate (see accompanying illustration). Check, replace clutch basket assembly.
The surface of the pressure plate or flywheel is scratched. Check, replace clutch basket or flywheel.
Note. Clutch vibration is usually most noticeable when backing up an incline. Since one of the causes of vibration is the weakening of the power unit mounts, before removing the clutch for inspection, carefully check the condition of the rubber pads and mount brackets, as well as the reliability of their fastening.
Clutch seizing occurs
Power unit mounts broken or loose (see accompanying illustration). Tighten fasteners or replace defective supports.
The working surface of the driven disk is contaminated with oil. Check, replace disk. Find the source of the leak and eliminate its cause.
Cracks appeared in the working surface of the pressure plate. Check, replace clutch basket assembly.
Clutch does not disengage
Excessive clutch pedal play. Perform pedal adjustment.
Air has entered the clutch hydraulic system. Bleed the hydraulic system.
Defective clutch slave cylinder. Check, overhaul or replace the cylinder.
Clutch master cylinder defective. Check, overhaul or replace the cylinder.
Defective clutch release mechanism. Check and make necessary repairs.
Driven disk bent. Check, replace disk.
The driven disk hub is jammed on the splines of the gearbox input shaft. Check, if necessary, replace the disc or the input shaft.
driven disk "stuck" to the flywheel due to moisture entering the clutch housing. Check the condition of the clutch, seal the casing.
Faulty servo unit (4.2 l models). Check, replace block.
Note. Since in most cases, incomplete clutch disengagement turns out to be due to a violation of the free play adjustment or the clutch pedal height setting before removing the clutch for inspection, carefully check the correct settings and bleed the hydraulic system.
Extraneous noise occurs during clutch operation
Exhausted or worn release bearing. Check, replace bearing.
Pressure plate diaphragm spring damaged. Check the spring petals for gouges and other damage (see accompanying illustration), replace the disc if necessary.
Worn or not lubricated input shaft guide bushing. Check and replace bushing if necessary.
Note. To check the noise emitted by the release bearing, lightly depress the clutch pedal while the engine is running. If the release bearing is defective and needs to be replaced, be sure to also check the condition of the other clutch components.